Although bank holding companies (BHCs) have existed for over three-quarters of a century, their impact on the banking and financial sectors has become significant only in the past decade. Prior to 1971 BHCs were divided into two basic types, multibank and one-bank holding companies. Multibank holding companies (MBHCs) were defined as corporate entities controlling at least 25 percent of the ownership of two or more banks and since 1956 have been required to register with the Board of Governors of the Federal Reserve System. Historically, MBHCs have been used largely to circumvent intrastate and interstate branch banking prohibitions, but in recent years they have been expanding into nonbanking areas.